Optimized Mine Ventilation System

ABSTRACT

The optimized mine ventilation system of this invention supplements mine ventilation basic control systems composed of PLCs (Programmable Logic Controllers with human machine interfaces from vendors such as Allen-Bradley™, Modicon™ and others) or DCSs (Distributed Control System from vendors such as ABB™ and others) with supervisory control establishing a dynamic ventilation demand as a function of real-time tracking of machinery and/or personnel location and where this demand is optimally distributed in the work zones via the mine ventilation network and where the energy required to ventilate is minimized while totally satisfying the demand for each work zones. The optimized mine ventilation system operates on the basis of a predictive dynamic simulation model of the mine ventilation network along with emulated control equipment such as fans and air flow regulators. The model always reaches an air mass flow balance where the pressure and density is preferably compensated for depth and accounts for the natural ventilation pressure flows due to temperature differences. Model setpoints are checked for safety bounds and sent to real physical control equipment via the basic control system.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present patent application claims the benefits of priority ofCanadian Patent Application No. 2,559,471, filed on Aug. 31, 2007, atthe Canadian Intellectual Property Office and entitled: “Undergroundcommunication network system for personal tracking and HVAC control”.

FIELD OF THE INVENTION

The present invention generally relates to mining undergroundventilation control and its optimization as a function of a dynamicdemand related to the tracking of the machinery location and/oroperating status and/or personnel location. More specifically it relatesto the predictive modeling and simulation along with the optimization ofthe air distribution and fans energy consumption to physically controlthe operating setpoints for fans and air flow regulators.

BACKGROUND OF THE INVENTION

FIG. 1 represents a typical mine ventilation layout with airflow controlequipment. The intent is not to generalize the FIG. 1 layout example toall mines, but to typically explain and associate the optimized mineventilation system application to mining ventilation. The optimized mineventilation system can be applied to an infinite variation of minelayout configurations.

As shown on FIG. 1 a mine is typically composed of the followingelements:

One or more intake fans [FIG. 1, element (2)] provide air from thesurface atmosphere to the underground infrastructure via one or moredowncast shafts [FIG. 1, element (3)]. The fans speed is manuallycontrolled by a local controller or by a basic control system withsurface HMI (Human Machine Interface). The control system usually alsoincludes startup and shutdown sequences and protection interlocks.

The downcast shaft(s) provides fresh air to working levels whereproduction occurs on one or more extraction zones off each level [FIG.1, elements (5, 6, 7)]. Ramps with or without access doors will alsodivert some air from each levels to other levels [FIG. 1, elements (8,9)]. Ramps provide a route for equipment to move from one level toanother.

Ore and waste material is extracted from the production zones by dieselmachinery and is dropped in ore or waste passes down to lower levels tobe crushed and brought back to the surface by conveyors in shafts [FIG.1, elements (26, 27)].

Air is forced from each level to the ore extraction zones or serviceareas [FIG. 1, elements (10, 11, 29, 12, 13, 14)] by auxiliary fans andducting connected to the fans [FIG. 1, elements (15, 16, 30, 17, 18,19)]. As per the surface fans, the auxiliary fans speed is manuallycontrolled by a local controller or by a basic control system withsurface HMI (Human Machine Interface). The diesel particulate emissioncontaminated air from the ore extraction zones comes back to the levelvia the ore extraction excavation.

Contaminated air is flowing to upcast shaft(s) [FIG. 1, element (4)].through fixed opening bulkheads or bulkheads with variable air flowregulators [FIG. 1, elements (23, 24, 25)]. The air flow regulatorsposition is manually controlled by a local controller or by a basiccontrol system with surface HMI (Human Machine Interface).

In some modern installations air flow measurement stations are found atthe bulkhead [FIG. 1, elements (20, 21, 22)].

Sometimes when the surface fans capacity is exceeded, lower levels willhave additional booster fans used as in-line pressure enhancers [FIG. 1,element (28)]. The fans speed is manually controlled by a localcontroller or by a basic control system with surface HMI (Human MachineInterface). The control system usually also includes startup andshutdown sequences and protection interlocks.

One or more exhaust fans [FIG. 1, element (1)] draw air from one or moreupcast shafts [FIG. 1, element (4)] out to the surface atmosphere. Thefans speed is manually controlled by a local controller or by a basiccontrol system with surface HMI (Human Machine Interface). The controlsystem usually also includes startup and shutdown sequences andprotection interlocks.

Traditionally the calculation of required setpoints for fans speed andbulkheads surface area opening or air flow regulator opening positionhas been achieved by manual survey results of air flows and regulatoryrequirements for maximum diesel equipment presence in one work zone. Inaddition, numerous mine operators use the calculation assistance ofcommercially available ventilation network steady state non real-timesimulators designed to simulate existing ventilation networks. Fanoperating points, airflow quantities, and frictional pressure drops areobtained from those calculations to assist derive physical operatingsetpoints.

There are several drawbacks and deficiencies in those fans speed andbulkhead opening setpoint calculations:

Surveys are spontaneous measurements and are not representative of thechanging operating environment of a live mine. Therefore, maximum safesetpoint values have to be used to be representative of the worst casescenarios.

Commercially available simulators lack one or more of the followingcapabilities rendering them unfit for live real-time control. They areeither non real-time calculation engines unfit for live control. Theirpressure and flow calculations may also omit the depth air columncompensation for air density and pressure calculation which createssignificant errors in the results also rendering them unfit for livereal-time control. Their flow calculations may not be compensated fornatural ventilation pressure flows from temperature differences. Thisalso renders them unfit for live real-time control.

The aforementioned control equipment setpoint calculation methods aretherefore used with limits and safety factors that cannot dynamicallyadjust to accommodate a live diesel machinery ventilation presence oftenwasting valuable air therefore not available to other work zones. Hence,those setpoint calculations do not offer a live dynamic optimization ofthe air flow routing and distribution. In conclusion, those productionventilation setpoint calculation methods often prohibits mine operatorsto access deep remote ore body sectors due to the lack of available air.

The optimized mine ventilation system has been engineered to circumventthose previously mentioned setpoint calculation deficiencies. Theoptimized mine ventilation system permits on-demand ventilation as perdynamic personnel location and dynamic diesel machinery location andoperating status. An optimized zonal ventilation demand is calculatedand the optimized mine ventilation system assures optimal air routingand distribution at minimum energy cost.

The optimized mine ventilation system does not require costly air flowsensors which typically have proven problem prone installations due tothe harsh mine air environment. Routine maintenance of those sensors istherefore eliminated. Only a few sensors will be required to keep a livecorrelation check with the model.

OBJECTS OF THE INVENTION

The objectives of this optimized mine ventilation system invention areto assist mine operators with:

-   -   A real-time production enhancement tool which optimizes the        underground air distribution to reach ore body sectors which        could not be reached with the current ventilation routing        procedures;    -   A real-time energy management tool that contributes in        diminishing the energy required to ventilate underground work        zones while maintaining target flow rates;    -   A real-time environmental management tool that contributes to        diminish the electrical power generation CO emission footprint        while also maintaining target flow rates.    -   A system that installs easily to existing or new control        infrastructure based on “Open Architecture” that connects        transparently, without programmatic developmental efforts to any        OPC (Ole for Process Control, see www.opcfoundation.org) based        control system.

Other and further objects and advantages of the present invention willbe obvious upon an understanding of the illustrative embodiments aboutto be described or will be indicated in the appended claims, and variousadvantages not referred to herein will occur to one skilled in the artupon employment of the invention in practice.

SUMMARY OF THE INVENTION

The aforesaid and other objectives of the present invention are realizedby a proper ventilation layout and related equipment parametricinformation configuration and installation of an optimized mineventilation system in accordance with this invention along with a basiccontrol system which modulates fans speed and air flow regulatorposition and which read few critical air flow measurements to correlatein real-time the results of the optimized mine ventilation systemmodeling and optimizer calculations.

FIG. 2 is a summary block diagram of the optimized mine ventilationsystem connection to external third party components.

The optimized mine ventilation system [FIG. 2, item (33)], requires thefollowing directly connected third party systems:

-   -   A tracking system providing data on the dynamic location and        operating status of the machinery [FIG. 2, item (34)].    -   A basic control system (such as PLCs or a DCS to execute local        control and to route fan speed setpoints to fans and regulator        opening setpoints to air flow regulators [FIG. 2, items (30, 31,        32)].

The optimized mine ventilation system [FIG. 2, item (33)] performs thefollowing general tasks:

-   -   Perform a dynamic air mass flow balance for the entire mine        ventilation network inclusive of all fans and air flow        regulators or fixed opening bulkheads.    -   From the dynamic tracking data, calculate each machinery        ventilation demand and personnel ventilation demand.    -   Perform a total ventilation demand for all machinery and/or        personnel present in each of the mine defined work zones (ore        extraction zones, service areas and levels).    -   Calculate the aggregate demand for each zone parent-child        relationship. For example, the total demand for a level is equal        to the total demand for all related ore extraction zones and        service areas plus the total demand related to machinery and        personnel directly tracked on the level.    -   Provide the demand to each of the zone related controllers:        auxiliary fans and air flow regulators.    -   Fans and airflow regulators can be controller in manual or        semi-automatic mode directly by the operator. A VOD control mode        uses tracking data to automatically modulate the fans and air        flow regulators as per the dynamic demand calculation.    -   When in VOD control mode, the controllers regulates the flow for        each zone as per the tracking and safety limits settings.    -   In VOD control mode, the surface fans cascade controller will        modulate the optimum air flow distribution ant the lowest fan        operating cost as per the cascade controllers set limits.    -   In VOD control mode, the setpoints are filtered for stability,        minimum time between up and down changes, ramp-up, ramp-down and        deadband before they are sent to the basic control system via        OPC connection.    -   Critical air flow measurements are monitored and correlated to        the modeled flows and when a discrepancy exists, the optimized        mine ventilation system calls for a survey and calibration.

The features of the present invention which are believed to be novel areset forth with particularity in the appended claims.

As a first aspect of the invention, there is provided a method ofoptimizing mine ventilation, the method comprising:

-   -   calculation of a ventilation demand of a zone of interest;    -   as a function of machinery location and operating status and        personnel location monitoring, determining an optimal quantity        of ventilation required for the zone of interest; and    -   remotely controlling a ventilation flow in the zone of interest        as a function of the determined optimal quantity of ventilation        required.

Preferably, the determining an optimal quantity of ventilation comprisescalculation of monitoring data using a ventilation system model adaptedto determine an optimal quantity of ventilation required in the zone ofinterest.

Preferably, the monitoring the zone of interest, the determining anoptimal quantity of ventilation and the remote controlling ofventilation equipment are carried out in real-time.

Preferably, the monitoring comprises monitoring presence of operatingmachinery and personnel inside the zone of interest and the monitoringdata comprises machinery-and-personal related data.

Preferably, the monitoring presence of operating machinery and personnelcomprises gathering the machinery-and-personal related data using amonitoring and communication system covering the zone of interest, wherethe machinery-and-personal related data comprises an indication of aquantity of operating machinery and personal present inside the zone ofinterest.

Preferably, the machinery-and-personal related data further comprises,if operating machinery is present in the zone of interest, an indicationif the machinery is diesel operated, and if it is the case, an engine orhydraulic-electric operating status of the machinery.

Preferably, the machinery-and-personal related data further comprises,if operating machinery is present in the zone of interest and themachinery is diesel operated, engine-characteristics related dataallowing for determining a total amount of horse power of the machinery.

Preferably, the controlling a ventilation flow in the zone of interestis carried out automatically.

Preferably, the presence of machinery is detected using a wirelesscommunication system.

Preferably, the presence of personal is detected using a wirelesscommunication system.

The presence of machinery can also be detected using a radio frequencyidentification system.

The presence of personal can also be detected using a radio frequencyidentification system.

The controlling a ventilation flow in the zone of interest is optionallymanually controlled by an operator.

Preferably, the triggering is carried out by the operator using agraphical Human-Machine-Interface allowing graphical visualization of aventilation status as per simulation model calculations of the zone ofinterest.

Preferably, the process of remotely controlling a ventilation flow inthe zone of interest comprises adjusting speed of fans and/or regulatorsposition.

As a further aspect of the invention, there is provided a system foroptimizing ventilation equipment, the system comprising:

-   -   a real-time simulation model based control system which        calculates air flow data in real-time for a zone of interest;    -   a real-time simulation model that calculates flow and pressure        as a function of the density and temperature variation which is        a function of depth;    -   a real-time simulation model that accounts for natural        ventilation pressure flows;    -   an optimizer for air flow distribution and fan energy        consumption connected to the simulation model unit, as a        function of an optimal quantity of ventilation required for the        zone of interest;    -   a real-time simulation model that will correlate physical air        flow measurements to modeled air flow calculations and in case        of discrepancies will have the capability to automatically        calibrate system components k factor resistance to match        physical measurements; and    -   a ventilation equipment controlling unit connected to the        optimal ventilation simulating unit and adapted to be connected        to a communication system for remotely controlling performance        of ventilation equipment as a function of the determined optimal        quantity of ventilation required.

Preferably, the remote controlling of ventilation equipment is triggeredautomatically upon reception, by the ventilation equipment controllingunit, the determined optimal quantity of ventilation required.

The system preferably further comprises a graphical image generatingmodule connected to the monitoring unit for generating, as a function ofthe calculated by modeling and received monitoring data, a graphicalimage of a current ventilation status of the zone of interest.

Preferably, the graphical image generating module is further connectedto the optimal ventilation simulating unit for generating, as a functionof the determined optimal quantity of ventilation required, a graphicalimage of an optimal ventilation status of the zone of interest.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the inventionwill become more readily apparent from the following description,reference being made to the accompanying drawings in which:

FIG. 1 is background information on a mine ventilation typical layoutand related air flow modulation equipment such as fans and airflowregulators within bulkheads. The optimized mine ventilation systeminvention models the ventilation air flow of the network and controlsphysical air flow modulation equipment.

FIG. 2 is a block diagram summary of all ventilation control componentsinclusive of an optimized mine, ventilation system.

FIG. 3 is a detailed block diagram of the optimized mine ventilationsystem invention components and links to external elements. Dashedcomponents are external elements to the optimized mine ventilationsystem.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

A novel optimized mine ventilation system will be described hereinafter.Although the invention is described in terms of specific illustrativeembodiment(s), it is to be understood that the embodiment(s) describedherein are by way of example only and that the scope of the invention isnot intended to be limited thereby.

An embodiment of the optimized mine ventilation system according to thepresent invention will be described below in detail with reference tothe drawings.

The following describes a summary of the optimized mine ventilationsystem functionality and links to external systems with references toFIG. 3.

A third party machinery and personnel tracking system provides real-timedata on the machinery location and operating status and on personnellocation [FIG. 3, item (55)].

From the dynamic tracking status of each machinery a ventilation demandis calculated for each defined mine work zones as per the following[FIG. 3, items (56, 57)]:

-   -   CFM or m3/s per diesel hp when diesel is “On”.    -   CFM or m3/s per diesel hp when diesel is “Off”. This permits        operations to have air available for machinery stopped at a        location with personnel around.    -   CFM or m3/s per diesel hp when the diesel is “Off” and its        hydraulic-electric is “On”.

Those three parameters are configurable per machinery by the surface orunderground operators.

The system calculates the aggregate demand for each zone parent-childrelationship from the zone definition database [FIG. 3, item (57)]. Forexample, the total demand for a level is equal to the total demand forall related ore extraction zones and service areas plus the total demandrelated to machinery and personnel directly tracked on the level.

The system sets to a minimum the personnel ventilation demandrequirement per zone and overrules the machinery calculation if thepersonnel demand is higher.

If the calculated personnel and machinery total demand while on VODcontrol mode, the VOD controller will set the zone flow to a minimum airflow as defined by the ventilation engineer.

The mine ventilation layout, fans and air flow regulators are created inthe form of an electronic process and instrumentation diagram using theSimsmart™ Engineering Suite modeling and simulation tool. Parametricinformation for all layout and control elements present on the diagramis configured in the diagram database [FIG. 3, item (52)]. The diagramis compiled into a run-time engine execution environment [FIG. 3, item(51)]. The run-time engine environment executes in real-time allphysics, characteristic, mathematics and logic based equations.

The Simsmart™ Engineering Suite run-time engine is responsible for thefollowing tasks:

-   -   As described above, to calculate the dynamic ventilation air        flow demand and summarized per defined mine area such as an ore        extraction zone, a level, a service area and other workplaces.    -   To model the ventilation network and establish an air flow mass        balance. The air density, pressure and temperature are        preferably compensated for depth. The real-time model execute        real-time calculations for pressure, fluid velocity, flow,        temperature, several other fluid properties, fan speed and        regulator position [FIG. 3, items (53)].    -   To execute controls in manual, semi-automatic and VOD mode to        optimize the air distribution and fan energy consumption based        on the calculated dynamic air flow demand [FIG. 3, item (54)].    -   To provide the required logic for fans and air flow regulators        setpoint scheduling [FIG. 3, items (63)].    -   To declare and handle alarm and special event conditions.

The following physics calculation assumptions describe the basicconcepts and equations used for the simulation model components and thereal-time resolution of the differential equations matrix [FIG. 3, item(51)]:

-   -   The simulation model uses compressible air flow with a        polytropic process. This is a process which occurs with an        interchange of both heat and work between the system and its        surroundings. The nonadiabatic expansion or compression of a        fluid is an example of a polytropic process. The        interrelationship between the pressure (P) and volume (V) and        pressure and temperature (T) for a gas undergoing a polytropic        process are given by Eqs. (1) and (2),

$\begin{matrix}{{PV}^{\; a} = c} & (1) \\{\frac{P^{b}}{T} = {c.}} & (2)\end{matrix}$

-   -   where a and b are the polytropic constants for the process of        interest. These constants, determined from mine surveys. Once        these constants are known, Eqs. (1) and (2) can be used with the        initial-state conditions (P₁ and T₁ or V₁) and one final-state        condition (for example, T₂, obtained from physical measurement)        to determine the pressure or specific volume of the final state.    -   Because density varies significantly, the air weight effect is        not negligible. In this case there is an auto compression        effect. Pressure variation not only causes density variation but        also causes temperature variation accordingly based on the        polytropic index.    -   The calculations account for Natural Ventilation Pressure (NVP).        NVP is the pressure created in a ventilation network due to the        density difference between air at the top and bottom of the        downcast and upcast shafts. In deep hot mines there is usually a        large difference between surface and underground        temperatures—there is a difference in density between air on        surface and underground and this causes air to move from high to        low density. The NVP will either assist or retard fans in the        system. When NVP assists a fan, it tends to move air in the same        direction as the fan. The NVP can be the to lower the system        resistance curve against which the fan operates. This means the        fan will handle more air at lower pressure.    -   The actual tunnel air resistance is calculated using the entered        standardized Atkinson resistance or the standardized Atkinson        friction factor.    -   The air pressure, air velocity, flow resistance and air flow        rate are calculated at all points in the system.    -   The pressure and density calculation accounts for air weight        (air potential pressure) and the Bernoulli Equation accounts for        potential energy.    -   Correction of fan specification curves with the density        variation effect.    -   Calculation of variable speed fan flow, pressure, power and        efficiency curves.    -   Ducting junctions, dovetails or transitions can calculate        process pressure and flow resistance for each port.    -   Transitions, junctions and fan calculation accounts for positive        and negative flow resistance.    -   All components calculate air properties: temperature, pressure,        viscosity, humidity, dew point temperature, particles, and        contaminant concentrations.    -   An iteration convergence method is used for transient simulation        modes.    -   Latent heat calculation is not available.

The ventilation demand calculation commands controllers to modulate fansand air flow regulators [FIG. 3, item (54)].

There are four types of regulatory controls for fans and air flowregulators in the optimized mine ventilation system:

Auxiliary Fans Control.

-   -   From the air mass flow balance calculations, the auxiliary fans        speed is modulated so the output flow at the exit of the ducting        section meets the calculated target demand flow for each work        zone.

Air Flow Regulator Controls for Levels.

-   -   From the air mass flow balance calculations, the air flow        regulator opening position is modulated so the regulator output        flow meets the calculated target demand flow for each work zone.    -   If an air flow regulator is in manual mode or if the regulator        is a fixed bulkhead opening, an intake compensation cascade        controller will modulate the surface fans in order to meet the        calculated target demand flow.

Surface Fans Controls.

-   -   The surface fan controller is a cascade controller [FIG. 3,        items (58, 59)] that optimizes the surface fan speeds in order        to minimize energy consumption while assuring all levels to        obtain their calculated target demand flow and maintaining a set        maximum regulator opening. This maximum regulator opening is the        cascade controller setpoint.    -   It is assumed that all surface fans are driven by a variable        frequency drive. As an example, if the surface fans cascade        controller setpoint is set at 80% opening maximum for any air        flow regulator, the surface fans will be modulated in order to        assure that any level air flow regulator will be at and not        exceed this 80% maximum opening.    -   The surface fans cascade controller calculates a common        modulated fan speed for all fans. This speed is then split by a        ratio to intake fans and to another ratio to exhausts fans.

Booster Fans Controls.

-   -   The booster fan controller is a cascade controller over the air        flow regulator controller. It will modulate the booster fan        speed based on set maximum air flow regulator opening. For        example if the cascade controller setpoint is set at 70%, this        means that when the booster fan will be modulated upward when        the regulator position exceeds 70%.

The optimized mine ventilation system has the following control modes[FIG. 3, item (54)].

Surface Operating Mode:

-   -   MAN: A fixed fan speed or regulator position setpoint is entered        by the surface operator. The fan speed and/or regulator position        not modulated automatically. The simulation model does not        modulate the fan speed or the airflow regulator position to meet        a CFM value. The machinery tracking has no effect on the        control. The local underground controller requires to be in        “Surface” mode.

AUT: This mode activates the selected VOD or CFM modes.

-   -   a. VOD: The CFM setpoint is calculated from the dynamic        machinery tracking results. The fan speed and/or regulator        position is automatically modulated to meet the CFM demand        setpoint as per the calculated actual flow by the simulation        model. The modulated fan speed or airflow regulator position        setpoint is sent to the underground physical device. The        controller also needs to be in AUT mode for the VOD mode to be        active. The controller also requires to be in “Surface” mode. A        minimum flow setting is available for the VOD mode. Therefore, a        dynamic tracking ventilation demand setpoint may never be lower        than a defined pre-set. The minimum flow presets are defined in        a purpose built HMI page.    -   b. CFM: The CFM setpoint is a fixed value and is entered by the        surface operator for fans or airflow regulator. The fan speed        and/or regulator position is automatically modulated to meet the        fixed value CFM setpoint as per the calculated actual flow by        the simulation model. The simulation model will modulate the fan        speed or the airflow regulator position to meet the desired CFM        value. The equipment tracking has no effect on the control. The        controller also needs to be in AUT mode for the CFM mode to be        active. The controller requires to be in “Surface” mode.

Underground Operating Mode:

-   -   Control is normally achieved from the surface, but an        underground operator via a tablet PC may acquire a control mode        called “Underground”. When he acquires control he can operate        the selected controller in Manual mode.

The surface operator receives an alarm when control is acquired by theunderground operator. The surface operator is requested to acknowledgethe alarm. When the alarm is acknowledged, the alarm conditiondisappears.

-   -   When the underground operator releases control back to the        surface operator, an alarm is displayed to the surface operator.        The surface operator is requested to acknowledge the alarm. When        the alarm is acknowledged, the alarm condition disappears.    -   When the control is released by the underground operator, the        selected controller goes back to the previous mode in use before        he acquired control.

The following describes each mode:

-   -   SUR: A fan speed and/or regulator position is set by the surface        operator in MAN, AUT (VOD/CFM) modes (see above).    -   UND: When a controller is set to UND, a fan speed and/or        regulator position is manually set by an underground operator        via a WIFI tablet PC HMI control page.

The VOD control mode setpoints are filtered [FIG. 3, item (65)] forstability, minimum time between up and down changes, ramp-up, ramp-downand deadband before they are sent to the basic control system andphysical fans and air flow regulators via OPC connection [FIG. 3, items(66, 67)].

Since not all mine ventilation operating procedures call for work zoneflow setpoints being calculated on machinery location, operating statusand personnel location, controller modes and setpoints are also subjectto scheduled or ad-hoc events [FIG. 3, item (63)]. Therefore, presetsfor each controller modes and setpoints can be configured for an arrayof user definable events [FIG. 3, item (64)]. Optionally, an autoswitchto tracking based ventilation (VOD mode) can be enabled when a minimumventilation demand has been detected by the dynamic tracking. Likewise,another autoswitch to tracking based ventilation can be enabled when adefined period of time has elapsed.

Scheduling presets can also cover specific events such as pre-blast andpost-blast events. The optimized mine ventilation system will warn theoperator if pre-blast event is set with remaining personnel andmachinery activity in the mine.

The optimized mine ventilation system monitors critical key air flowmeasurements [FIG. 3, item (60)] and will alarm when a correlationdeviation to the measurements calculated by the model [FIG. 3, item(61)]. The optimized mine ventilation system will call for a flow surveyto verify if the measurement instrument or the calculated flow are inerror. If it is concluded that the calculated flow must be calibrated,the ventilation engineer will set the related flow controller incalibration mode. Then, it will automatically adjust the related systemportion calculated k factor to match the survey data.

While illustrative and presently preferred embodiment(s) of theinvention have been described in detail hereinabove, it is to beunderstood that the inventive concepts may be otherwise variouslyembodied and employed and that the appended claims are intended to beconstrued to include such variations except insofar as limited by theprior art. Indeed, the system of the invention can be used in anyconfined environment where there is a need for ventilation as a functionof the presence of humans, animals and/or equipment, for example:tunnels.

1. A method of optimizing mine ventilation, the method comprising:calculation of a ventilation demand of a zone of interest; as a functionof machinery location and operating status and personnel locationmonitoring, determining an optimal quantity of ventilation required forsaid zone of interest; and remotely controlling a ventilation flow insaid zone of interest as a function of said determined optimal quantityof ventilation required.
 2. The method as claimed in claim 1, whereinsaid determining an optimal quantity of ventilation comprises:calculation of monitoring data using a ventilation system model adaptedto determine an optimal quantity of ventilation required in said zone ofinterest.
 3. The method as claimed in claim 2, wherein said monitoringsaid zone of interest, said determining an optimal quantity ofventilation and said remote controlling of ventilation equipment arecarried out in real-time.
 4. The method as claimed in claim 3, whereinsaid monitoring comprises monitoring presence of operating machinery andpersonnel inside said zone of interest and said monitoring datacomprises machinery-and-personnel related data.
 5. The method as claimedin claim 4, wherein said monitoring presence of operating machinery andpersonnel comprises gathering said machinery-and-personnel related datausing a monitoring and communication system covering said zone ofinterest, where said machinery-and-personnel related data comprises anindication of a quantity of operating machinery and personnel presentinside said zone of interest.
 6. The method as claimed in claim 5,wherein said machinery-and-personnel related data further comprises, ifoperating machinery is present in said zone of interest, an indicationif said machinery is diesel operated, and if it is the case, an engineor hydraulic-electric operating status of said machinery.
 7. The methodas claimed in claim 6, wherein said machinery-and-personnel related datafurther comprises, if operating machinery is present in said zone ofinterest and said machinery is diesel operated, engine-characteristicsrelated data allowing for determining a total amount of horse power ofsaid machinery.
 8. The method as claimed in claim 7, wherein saidcontrolling a ventilation flow in said zone of interest is carried outby modulating speed of fans and/or regulators position.
 9. The method asclaimed in claim 8, wherein the presence of machinery is detected usinga wireless communication system.
 10. The method as claimed in claim 8,wherein the presence of personnel is detected using a wirelesscommunication system.
 11. The method as claimed in claim 9, wherein thepresence of machinery is detected using a radio frequency identificationsystem.
 12. The method as claimed in claim 10, wherein the presence ofpersonnel is detected using a radio frequency identification system. 13.The method as claimed in claim 7, wherein said controlling a ventilationflow in said zone of interest is optionally manually controlled by anoperator.
 14. The method as claimed in claim 13, wherein said manualcontrol is carried out by said operator using a graphicalHuman-Machine-Interface allowing graphical visualization of aventilation status as per simulation model calculations of said zone ofinterest.
 15. The method as claimed in claim 14, wherein said remotelycontrolling a ventilation flow in said zone of interest comprisesadjusting speed of fans and/or regulators position.
 16. A system foroptimizing ventilation equipment, the system comprising: a real-timesimulation model based control system which calculates air flow data inreal-time for a zone of interest; a real-time simulation model thatcalculates flow and pressure as a function of the density andtemperature variation which is a function of depth; a real-timesimulation model that accounts for natural ventilation pressure flows;an optimizer for air flow distribution and fan energy consumptionconnected to said simulation model unit, as a function of an optimalquantity of ventilation required for said zone of interest; a real-timesimulation model that will correlate physical air flow measurements tomodeled air flow calculations and in case of discrepancies will have thecapability to automatically calibrate system components k factorresistance to match physical measurements; and a ventilation equipmentcontrolling unit connected to said optimal ventilation simulating unitand adapted to be connected to a communication system for remotelycontrolling performance of ventilation equipment as a function of saiddetermined optimal quantity of ventilation required.
 17. The system asclaimed in claim 16, wherein said remote controlling of ventilationequipment is triggered upon reception, by said ventilation equipmentcontrolling unit, of said determined optimal quantity of ventilationrequired.
 18. The system as claimed in claim 16, further comprising agraphical image generating module connected to said monitoring unit forgenerating, as a function of said calculated by modeling and receivedmonitoring data, a graphical image of a current ventilation status ofsaid zone of interest.
 19. The system as claimed in claim 18, whereinsaid graphical image generating module is further connected to saidoptimal ventilation simulating unit for generating, as a function ofsaid determined optimal quantity of ventilation required, a graphicalimage of an optimal ventilation status of said zone of interest.